Balers for forming cylindrical bales are of a fixed chamber or a variable chamber type. Such devices are known as such in different configurations.
Document EP 1 077 025 B1 discloses a baler apparatus working as follows. The grass is picked-up by adequate means, formed and pressed into a bale in a baling chamber by rollers, belts or like engaging means. When baling is complete, second means apply a strip of netting around the cylindrical outer surface of the bale in the same chamber. Afterwards the rear portion of the baling chamber is raised and the bale is transferred to third means for applying stretch film which is located behind the baling chamber by conveyer means. During the transfer of the bale to the third means for applying the stretch film, the rear portion of the baling chamber is lowered and thereafter the compression of a new bale can start. At the same time, the wrapping of the bale arranged by the third means for applying the stretch film is started. After wrapping the bale, the bale is put down on the ground by according forth means. Afterwards the cycle starts again.
Document EP 1 205 102 B1 describes a baler apparatus which is capable in situ, of forming a cylindrical bale, applying a partial envelope of netting around the cylindrical surface of the bale, and applying stretch film wrapping to the bale in the same baling chamber. The cycles for baling and packaging with this apparatus are as follows. A cylindrical bale is formed by supplying material to be baled to the chamber. Rollers, belts or like engaging means assist the forming of the bale. Means for applying a strip of netting around the cylindrical outer surface form at least one layer of netting thereon. One part of the baler chamber is raised and at the same time as the rotation stops. A stretching film is applied by means which are fastened to a rotating ring that surrounds the round bale in the baling chamber. The round bale is then put down on the ground and the cycle can start again.
Balers as described above have a common disadvantage. With those balers it is necessary to tie the bales within netting material prior to wrapping as otherwise the bale will break apart upon ejection from the baling machine or by simply opening the baling chamber. Furthermore the need for tying the bales is costly, because means for applying netting material must be provided. More particularly, the provision of netting material on cylindrical bales means also a great disadvantage for the fanner because he has to cut off the netting material before feeding out the fodder. Another risk is that the cylindrical bale may unroll during the feeding out operation.
Document GB 2 158 111 describes the use of special machines for removing the netting material. The need for use of such machines is another disadvantage regarding cost efficiency.
Document EP 1 352 554 B1 discloses a combined compacting and wrapping machine. The machine is provided with a compacting and wrapping station, and a wrapping and tipping station. In operation, a bale is formed in the compacting and wrapping station in a baling chamber. Following, in the compacting and wrapping station the baling chamber is raised vertically along columns by means of hydraulic rams. The upward travel of the chamber exposes the bottom portion of the compacted bale which rests on a platform. A film dispenser is than rotated around the exposed cylindrical surface of the bale to wrap the bale with plastics firm from the dispenser and continues to operate until all the exposed surface of the bale is wrapped, including an overlap of the bottom and top corners of the bale. After such first wrapping the bale is provided to the wrapping and tipping station located on the rear side of the apparatus and separately from the compacting and wrapping station. Following, the bale is wrapped in the wrapping and tipping station, and finally the bale is expelled from the apparatus.